#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <AccelStepper.h>

const int maxSpeed = 1000;  
const int motor1_in1 = 10;          
const int motor1_in2 = 9;          
const int motor1_in3 = 8; 
const int motor1_in4 = 7; 

const int motor2_in1 = 6;          
const int motor2_in2 = 5;          
const int motor2_in3 = 4; 
const int motor2_in4 = 3; 

const int btn1 = A0;          
const int btn2 = A1;          
const int btn3 = A2; 
const int btn4 = A3; 

LiquidCrystal_I2C lcd(0x27, 16, 2); 
//AccelStepper stepper1(AccelStepper::FULL4WIRE, motor1_in1, motor1_in2, motor1_in3, motor1_in4);
//AccelStepper stepper2(AccelStepper::FULL4WIRE, motor2_in1, motor2_in2, motor2_in3, motor2_in4);
AccelStepper stepper1(AccelStepper::FULL2WIRE, motor1_in1, motor1_in2);
AccelStepper stepper2(AccelStepper::FULL2WIRE, motor2_in1, motor2_in2);

unsigned long timeLcd, timeBtn;
int speed1, speed2;

void setup() {
  stepper1.setMaxSpeed(maxSpeed);
  stepper2.setMaxSpeed(maxSpeed);

  pinMode(btn1, INPUT_PULLUP);
  pinMode(btn2, INPUT_PULLUP);
  pinMode(btn3, INPUT_PULLUP);
  pinMode(btn4, INPUT_PULLUP);

  lcd.init(); 
  lcd.backlight(); 
  lcd.clear(); 
}

void handleButtons(){
    if(millis() - timeBtn > 100){
      timeBtn = millis();

      speed1 = digitalRead(btn1) == HIGH ? speed1 - 1 : speed1;
      speed1 = digitalRead(btn2) == HIGH ? speed1 + 1 : speed1;
      speed2 = digitalRead(btn3) == HIGH ? speed2 - 1 : speed2;
      speed2 = digitalRead(btn4) == HIGH ? speed2 + 1 : speed2;

      speed1 = constrain(speed1, 0, 100);
      speed2 = constrain(speed2, 0, 100);
    }
}

void handleLcd(){
  if(millis() - timeLcd > 100){
    timeLcd = millis();
    char buff[20];

    sprintf(buff, "Motor1: %3d %%", speed1);
    lcd.setCursor(0, 0);
    lcd.print(buff);

    sprintf(buff, "Motor2: %3d %%", speed2);
    lcd.setCursor(0, 1);
    lcd.print(buff);
  }
}

void loop() {
  stepper1.setSpeed(map(speed1, 0, 100, 0, maxSpeed));
  stepper2.setSpeed(map(speed2, 0, 100, 0, maxSpeed));

  stepper1.runSpeed();  
  stepper2.runSpeed();

  handleButtons();
  handleLcd();
}